Foot pedal control rheostat



Feb.,1, 1949. B. EISENBERG ET AL FOOT PEDAL CONTROL RHEOSTAT Filed July 15, 1946 INVENTORS BEN EISENBERG BY OTTO B. SCHWARZ TTORNEY Patented Feb. 1, 1949 UNITED STATES PATENT GFFICE FOO` PEDAL CONTROL EEES-STAT Ben Eisenberg, Larchinont, and Otto B. Schwarz,

New York, N. Y., assignors to Lelrtra Laboratories, Inc., a corporation of New York Application July 13, 1946, Serial No. 683,494

(Cl. B01-48) 4 Claims. l

The present invention relates to improvements in pedal control devices, and more particularly to improvements in pedal control devices for controlling electrical musical instruments or the like.

At the present time, there exist several types of musical instruments which produce musical sound by means of electrical amplifier and loudspeaker arrangements. One example of such an instrument is known as the electrical guitar. In nstruments of this type, the musician must use both hands in playing the instrument properly. However, a necessary adjunct of such instruments is a convenient control for the amplifier and loudspeaker, to increase the number and range of the various musical eilects produced. A useful control device should be able to vary continuously .both the tonal quality and the volume of the musical output, with a minimum hindrance to the normal playing upon the instrument itself.

These advantages are gained by the present invention, in which a single foot-operated control of novel and improved construction is adapted to adjust both the volume and tonal quality of the output from a musical system of the abovedescribed type.

According to the present invention, a single foot-operated member is adapted to be rotatably adjusted about two independent axes, one generally horizontal and the other generally vertical. Variable rheostats or potentiometers are mounted in novel fashion so as to be independently controllable and actuatable by adjustment of the foot-operated or pedal member, such rheostats or potentiometers being included in suitable manner in the input to the ampliiier-loudspeaker circuit so as to control volume and tone oi the output.

Accordingly, it is an object oi' the present invention to provide an improved pedal control device adapted for simultaneous, independent and continuous control of two separate electrical factors in an electrical musical instrument system or 'the like.

A `further object oi the present invention is to provide an improved pedal control device for independently actuating a pair of variable resistance devices.

Other objects and advantages will become apparent from the following description and from the attached drawing, in which Fig. 1 is a side elevation view of a preferred embodiment of the invention;

Fig. 2 is a top View, partly broken away, `of the device of Fig. 1, viewed along line 2--2 thereof;

ig. 3 is a side elevation view partly in crosssection of the device of Figs. l and 2, taken along line 3 3 oi Fig. 2; and

4i is a schematic circuit diagram of the device of the preceding figures.

The novel foot pedal control 'illustrated in the drawing has three separate sections. These are a base il, a pedal l2 and a rocker section I3. Base il comprises a fiat portion il and a thin vertically extending sheil l preferably integrally formed therewith, and extending around part of the periphery of the flat portion il. As will be seen, the shell i8 serves to conceal and protect the mechanism and circuit elements of the device, and to serve as a support for the rocker section i3 and the pedal l2.

Rocker section t3 also comprises a flat portion i9 and a shell lil extending generally perpendicularly downward therefrom and around a part of thc periphery thereof. Rocker shell l5 also extends around shell while spaced therefrom, to enable relative motion therebetween, as described below. Rocker shell it also encloses part of the mechanism, and together with base shell it forms a pleasing exterior and protective casing for the device.

The rocker section i3 is pivotaliy mounted on the base il by a pair of pivots, each of which, by way oi example, may comprise a screw l passing freely through the rocker shell iii and threaded into the base shell i3. A bushing may be used around each screw i5.- to provide a smooth pivot bearing.

The flat portion ii oi base il is formed with a boss 2l which carries a soft resilient bumper 22, such as of soit rubber, which cooperates with a boss 23 formed on the rocker dat portion i9 to serve as a stop for clockwise motion of the rocker section about the pivot screws i4. A similar stop may be used for counter-clockwise movement. The base 'dat portion ll also carries suitable soit base cushions 2li which prevent slippage of the device when placed on the floor and operated.

The pedal i2 is pvotally mounted upon the rocker section i3 for lateral movement with respect thereto, by means of a pivot screw 25 extending freely and perpendiculariy through the pedal i2 and screwed into the rocker dat portion i9. Pedal i2 carries a pair of hardened steel bearing plates 2 cooperating with hardened steel bearing balls 2B suitably mounted upon the rocker flat portion i9 to facilitate easy and continuous adjustment oi pedal i2 about the pivot screw 26. Pedal l2 also has formed thereon a heel-receiving lip 29 and a pair of side lips 3I to make it easier for the musicians foot to rotatably adjust the pedal I2 about the pivots 26 and I4. Also, the upper surface of pedal I2 is preferably made ribbed as at 32 to increase friction between the foot and the pedal, and to improve its appearance. A pair of pins are fixed to pedal i2 and extend within rocker shell I6 through an opening in the rocker fiat portion I9. Pins 30 provide stops for the lateral motion of pedal I2, by coaction with the side walls of rocker shell I5.

Formed on rocker section I3 within shell I6 is a downwardly depending flange 33 which carries a potentiometer 34 having a rotatable actuating shaft 35 to which is iixed a pinion 31. Engaging pinion 31 is a linear rack 38 pivoted at 39 to an upstanding member 4I xed to base II. A tension spring 42 extends between member 4I and rack 38, and maintains the rack 38 in engagement with pinion 31. section I3 is pivoted about pivot screws I4, pinion .31 rides up and down on rack 38 and turns rheostat shaft 36 to Vary the setting of potentiometer 34. The use of pivoted linear rack 38 avoids the necessity of using a circular rack, and moreover serves equally as well and is much simpler to manufacture and assemble. Y

Also formed on rocker section I3 is a substantially flat support 43 parallel to at portion I9 which carries a pair of ganged potentiometers 44, 4G having a single actuating shaft 4l to which is xed a pinion 48. Engaging pinion 48 is a second linear rack 49 which is pivotally mounted on pedal I2 at its center 5I. A bowed single-leaf spring 52 xed at one end to rocker section I3 with the center of its bow opposite pinion 48 keeps rack 49 in engagement with pinion 49. Thus, as pedal I2 is rotated about its pivot 26, rack 49 is moved substantially horizontally and rotates pinion 48 to adjust potentiometers 44, 46. The central pivot 5I of rack 49 permits it to turn slightly to keep in engagement with pinion 48 in all positions, and avoids the necessity of a circular rack. The spring 52 remains always opposite pinion 48, and is thus always effective no matter what the position of rack 49 may be.

The device described above accordingly providesa ready adjustment of two independent sets of rheostats or potentiometers 34 and 44, 46 by a single pedal I2 upon up-down rotation about a irst horizontal axis and lateral rotation about a second substantially vertical axis perpendicular vto the first axis. This provides a desirable control especially useful for electrical musical instruments requiring simpliiied control for two separate characteristics, such as volume or tone. Fig. 4 shows an exemplary circuit in which the present control has notable utility. This circuit includes a two-conductor plug 54 adapted to be plugged into the output of the electrical instrument, for example, and connected by a cable 5S to a simple terminal strip 5l' mounted on base I I. Rocker section I3 carries several condensers 58, 59 connected to terminal strip 5l and potentiometers 34, 44, 49 by flexible Wires 6I, G2, 53, in the manner shown by the circuit diagram of Fig. 4.

One terminal of plug 54 is grounded as at E?, while the other is connected to the variable tap 68 of potentiometer 44 across whose outer terminals condenser 59 is connected. One of these outer terminals of potentiometer 44 is also grounded at 61. The tap '68 is connected through the parallel-connected condenser 58 andY rheostat 4S to one outer terminal of potentiometer 34, Whose other outer terminal is grounded. The

Accordingly, as rocker .CAB

variable tap 'II and ground 61 are connected to an output jack 66, adapted to receive a plug similar to plug 54, but connected to the amplier and loudspeaker unit, for example, which is mounted on the side wall of base shell I8.

Ganged potentiometers 44, 46 actuated by lateral movement of pedal I2 adjust the tone quality of the musical output. Potentiometer 34, actuated by vertical movement of pedal I2, adjusts the volume of the musical output. Thus the pedal control unit of the present invention is readily coupled into the system in which it is to be used, While still remaining as a separate, compact and simple unit of pleasing appearance.

It will be understood that the details of the device described above are susceptible of variation as to their specic features, and that the scope of the present invention is not to be restricted to the illustrative embodiment herein described and shown, but is as defined in the appended claims.

What is claimed as the invention is:

l. A foot pedal control for musical instruments or the like comprising a base, a rocker pivotally mounted on said base for vertical rotation about a substantially horizontal axis, a pedal pivotally mounted on said rocker for lateral rotation about an axis perpendicular to said horizontal axis, a rst variable resistance device carried by said rocker and having a control shaft, a first pinion iixed to said control shaft, a linear rack pivotally connected at one end to said base and engaging said pinion, a first spring urging said rack toward said pinion, a second variable resistance device carried by said rocker and having a control shaft, a second pinion fixed to said latter control shaft, a second linear rack pivotally mounted at its center to said pedal, and a bowed spring xed to said pedal and urging said rack into engagement with said pinion, said spring having its maximum bow opposite said second pinion, whereby lateral adjustment of said pedal about said perpendicular -axis adjusts said second resistance device and vertical adjustment of said pedal about said horizontal axis adjusts Asaid rst resistance device.

2. A foot pedal control device comprising a rst relatively stationary member, a second footoperated relatively movable member, a Variable circuit element carried by one of said members and having a variable control shaft, a pinion fixed to said shaft, a linear rack pivotally connected atv its center to the other of said members, and a bowed flat spring xed to said one member and urging said rack toward said pinion, said springV having its bow opposite said pinion.

3. A foot pedal control for musical instrumentsor the like comprising a base, a rocker memberpivotally mounted on said base, a pedal pivotally mounted on said rocker member, a first variable circuit element carried by said rocker member and having a rst control shaft, a first pinion xed to said shaft, a rst rack pivotally connected at one end to said base and resiliently urged into engagement with said pinion, a second variable circuit element carried by said rocker member and having a second control shaft, a second pinion xed to said second shaft, a second rack pivotally mounted on said pedal and resiliently urged into engagement with said second pinion, whereby said two circuit elements may be independently actuated by adjustment of said pedal in two directions. Y

4. A variable control for an adjustable resistance device having a movable element, comprising a support adapted Ato rotatably hold said ele- 5 6 ment, a pinion fixed to said element, a bowed leaf spring on said support, and a linear rack REFERENCES CITED engaging said pinion and pressed by said spring The following references are of record in the toward said pinion, and an adjustable member, l Of this patenti said rack being pivotaiiy fixed at its center to said 5 UNITED STATES PATENTS adjustable member, whereby upon movement of said member, said movable element is adjusted Number Name Date correspondingly 2,139,217 Ama Dec. e, 193s BEN EISEN-BERG. 2,379,774 WYEI' July 3, 1945 OTTO B. SCHWARZ. 10 

